border-block-start

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨enero de 2020⁩.

Experimental: Esta es una tecnología experimental
Comprueba la Tabla de compabilidad de navegadores cuidadosamente antes de usarla en producción.

La propiedad de CSS border-block-start es una propiedad abreviada para establecer los valores lógicos individuales del borde de bloque inicial en un solo lugar en la hoja de estilos.

Pruébalo

border-block-start: solid;
writing-mode: horizontal-tb;

border-block-start: dashed red;
writing-mode: vertical-rl;

border-block-start: 1rem solid;
writing-mode: horizontal-tb;

border-block-start: thick double #32a1ce;
writing-mode: vertical-lr;

<section class="default-example" id="default-example">
  <div class="transition-all" id="example-element">
    This is a box with a border around it.
  </div>
</section>

#example-element {
  background-color: #eee;
  color: #8b008b;
  padding: 0.75em;
  width: 80%;
  height: 100px;
  unicode-bidi: bidi-override;
}

Sintaxis

css

border-block-start: 1px;
border-block-start: 2px dotted;
border-block-start: medium dashed blue;

border-block-start puede ser usado para establecer los valores de uno o más de border-block-start-width, border-block-start-style, y border-block-start-color. El borde físico al que se asigna depende del modo de escritura, la direccionalidad y la orientación del texto del elemento. Esto corresponde a las propiedades border-top, border-right, border-bottom, o border-left dependiendo de los valores definidos para writing-mode, direction, y text-orientation.

Propiedades relacionadas son border-block-end, border-inline-start, y border-inline-end, que definen los otros bordes del elemento.

Valor inicial	as each of the properties of the shorthand: `border-width`: as each of the properties of the shorthand: `border-top-width`: `medium` `border-right-width`: `medium` `border-bottom-width`: `medium` `border-left-width`: `medium` `border-style`: as each of the properties of the shorthand: `border-top-style`: `none` `border-right-style`: `none` `border-bottom-style`: `none` `border-left-style`: `none` `color`: `canvastext`
Applies to	all elements
Heredable	no
Valor calculado	as each of the properties of the shorthand: `border-width`: as each of the properties of the shorthand: `border-bottom-width`: the absolute length or `0` if `border-bottom-style` is `none` or `hidden` `border-left-width`: the absolute length or `0` if `border-left-style` is `none` or `hidden` `border-right-width`: the absolute length or `0` if `border-right-style` is `none` or `hidden` `border-top-width`: the absolute length or `0` if `border-top-style` is `none` or `hidden` `border-style`: as each of the properties of the shorthand: `border-bottom-style`: como se especifica `border-left-style`: como se especifica `border-right-style`: como se especifica `border-top-style`: como se especifica `border-block-start-color`: computed color
Animation type	as each of the properties of the shorthand: `border-block-start-color`: by computed value type `border-block-start-style`: discrete `border-block-start-width`: by computed value type

Valores

El border-block-start es especificado con uno o más de los siguientes valores, en cualquier orden:

<'border-width'>: El ancho del borde. Mira border-width.
<'border-style'>: El estilo de la línea del borde. Mira border-style.
<'color'>: El color del borde. Mira color.

Sintaxis formal

border-block-start = 
  <line-width>  ||
  <line-style>  ||
  <color>       

<line-width> = 
  <length [0,∞]>  |
  thin            |
  medium          |
  thick           

<line-style> = 
  none    |
  hidden  |
  dotted  |
  dashed  |
  solid   |
  double  |
  groove  |
  ridge   |
  inset   |
  outset

Ejemplo

Contenido HTML

html

<div>
  <p class="exampleText">Example text</p>
</div>

Contenido CSS

css

div {
  background-color: yellow;
  width: 120px;
  height: 120px;
}

.exampleText {
  writing-mode: vertical-rl;
  border-block-start: 5px dashed blue;
}

Especificaciones

Specification
CSS Logical Properties and Values Level 1 # border-shorthands

Compatibilidad con navegadores

Mira también

Esta propiedad se asigna a una de las propiedades del borde físico: border-top, border-right, border-bottom, o border-left.
writing-mode, direction, text-orientation

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This page was last modified on ⁨22 jul 2025⁩ by MDN contributors.

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